Direction finder



June 14, 1938. A. LElB El AL DIRECTION FINDER Filed Feb. 6, 1935 1NVENTORS.

ATTORNEY.

Patented June 14, 1938 TE STATES PATENT FFlE many, assignors toTelefunkcn Gesellschaft fiir Drahtlose Telegraphic m.

b. H., Berlin,

Germany, a corporation of Germany Application February 6, 1935, SerialNo. 5,199% In Germany January 30, 1934 8 Claims.

' stood by referring to the accompanying drawing, in which Fig. 1 is anelevation of a simple direction Fig. 2 is another modification which isgenerally similar to that of Fig. l, and

Fig. 3 is an elevation of an improved direction finder wherein thereceiver is rotated with the l direction finder.

Figure 1 shows schematically such Adcock direction finder in itssimplest shape. The dipoles a, a and a, a, respectively, are connectedto each other by means of horizontal leads I) and b and two lines 6connect them to the receiver. The dipoles are supported by a crosstubing d shielding the leads I), b and fixedly connected with thevertical turnable tube 1 containing the leads e. g designates aturnhandle, h is a bearing, and y is the scale indicating the angle ofthe turning. In such a construction of the Adcock direction finder thecapacity of the lead-ins is large as regards the capacity of the dipolesand a part of the receiving energy received by the dipoles thus becomeslost. Hence, with the Adcock direction finder according to Figure 1, thesharpness of the direction finding obtainable therewith is very poor.

In another embodiment of the Adcock directionfinder, the losses in theleads to the receiver are avoided by arranging the first or severalamplifier stages, or the receiver proper, in the turnable support of thedipoles proper, suitably in the enlarged space formed in the upper partof the turnable tubing 1 at its place of connection with the crosstubing 11. This is illustrated, for instance, in Figure 2, according towhich the first stage (input stage. of the receiver) represented by thetube 70 is mounted within the enlarged space Z. The dipoles may herebybe inductively, capacitively or galvanically connected to themputcircuit of the first stage. In Figure 2, an inductive coupling is shownby means of transformers Z, Z.

This arrangement produces much more favorable sharpness in the directionfinding than the arrangement according to Figure 1. However, it has thedisadvantage that all switching-tuning-and coupling elements must beoperated by way of distant control from the bottom. Due to this distantoperation and the turning tube there also exists a capacitive asymmetryof the dipoles. The capacity of the lower rods of the dipoles is greaterwith respect to the turning tube, the 7 receiver and ground than is thecapacity of the upper rods.

These disadvantages are avoided in accordance with this invention by soconstructing the Adcock direction finder that the housing of the I roomfor finding the direction and containing 10 the receiver apparatus,batteries, drive for the direction finder and space for the operator,supports the Adcock dipoles and is turnably mounted upon a suitablestand, for instance, the tower of the, direction finder. The mountingcan be '15 carried out in such manner that the housing when turningcarries therewith the entire content of the direction finding room, orelse that only the housing is turnable while the content of thedirection finding room contained in the housing, hence the receiver, thebatteries, the space for the operator and the drive are fixedly mountedon the base.

An embodiment of the arrangement in accordance with the invention isshown in Figure 3, by way of example, wherein the receiver designated byE, the batteries designated by B and the drive A, together with thebearing scale and the space for the operator, are arranged Within a roomP shielded by the housing G and rotate 130 with the housing. On the sideof the housing the cross supports D, D are fixedly secured, the lattersupporting the dipoles of the direction finder. The housing G isrotatably mounted on a base U, for instance, by means of wheels 1. Thebase may consist of non-conducting material, for instance, Wood, inorder to avoid electrical, in particular capacitive, asymmetry of thedipoles. The turning of the direction finding room, together with thedirection finding antenna, is carried out by the operator manually or bymeans of a motor. The horizontal dipole lines b, b are directlyconnected to the receiver. The supporting arms D, D can serve. asshields for the horizontal dipole lines. In this described arrangementthere is also avoided a change of the capacity of the dipoles resultingfrom the movements of the operator, since the latter is within theshielded direction finding room.

Such arrangement is very well suited, in par ticular, for the directionfinding of longer waves of the navigation-air-and marine service. Wheresuch a direction finder is to be set up on a flying field or in directvicinity thereof, it should be so dimensioned that the greatest heightof the antenna of the antenna arrangement does not exceed 10 meters, soas to eliminate any possible hindrance in the movement of the airplanes.It is advisable to shield electrically the horizontal connections I), b,by means of a suitable shield (unless the supporting arms D, D furnishthis shield) and to conductingly connect this shield to the shieldinghousing G. As regards the housing, itself, the same can be composed ofnon-conducting material, provided with a metallic shield' in the form ofa net or cage. Rurthermore, the ar.

rangement is advisably such that this shield can be grounded orinsulated from the ground at will; during the pauses in the operationthe grounding of the shield will then be sustained, during operation thegrounding can be interrupted at will by employing a suitable lightningprotector.

We claim: a

1. A rotatable direction finder comprising a central housing havingspace for an operator, receiving apparatus, direction finder scale, andmeans for rotating said direction finder, two dipoles each one of whichis fixedly secured to an arm extending outward from the sides of thehousing, said housing being mounted for rotation upon the upper portionof a direction finder tower.

2. A rotatable direction finder according to claim 1, characterized inthat the upper portion of said tower consists of a platform ofnon-conducting material.

3. A rotatable direction finder comprising a supporting tower for acentral housing having space for an operator, receiving apparatus,direction finder scale, and means for rotating said direction finder,two dipoles each one of which is fixedly secured to an arm extendingoutward from the sides of the housing, said housing and said arm beingprovided with a metallic shield to shield the horizontal leads whichconnect the dipoles with a receiver, and means for rotating said housingon a platform located on the top of said supporting tower. V

i. A rotatable direction finder comprising a supporting tower, a centralhousing pivotally located on the top of said supporting tower, saidcentral housing having space for an operator, receiving apparatus,direction finder scale, and means for rotating said direction finder,two dipoles each one of which is fixedly secured to an arm extendingoutward from said housing, a

"sides of said housing,

' dipoles fixedly secured bearing centrally located on the top of saidtower, a plurality of rotatable elements secured to said centralhousing, and means within said housing for rotating the housing aroundsaid bearing. 7 v

5. A rotatable direction finder comprising a supporting, tower having anupper platform, a.

central shielded housing, two dipoles fixedly secured to an armextending outward from the a bearing centrally lo? a plurality ofrotatable under side of said houscated on said platform, elementssecured to the ing and arranged for rotation on said upper platform, andmeans Within said housing for rotating the same around said bearing.

6. A rotatable direction finder comprising a' supporting tower having anupper insulating platform, a central housing pivotally located in thecentral portion of said upper platform, two to an arm extending out:ward from thesides of said housing, a plurality of rotatable elementssecured to the under side of said housing and arranged for rotationonsaid insulating platform, and means within said housing for rotating thesame on said platform".

7. A rotatable direction finder comprising a supporting tower having anupper platform of insuiating material, a shielded housing pivotallysecured to the central portion of said platform, said housing having twodipoles fixedly secured to an arm extending outward from the sides ofsaid housing, a plurality of rotatable elements secured to the underside of said housing and arranged for rotation on said upper platform,and means within said housing for rotating the housing on said platform.

8. A rotatable direction finder comprising a supporting tower havingspace for an operator and the entire receiving and directional scaleequipment pivotally secured to the centralportion of said platform, saidhousing having two dipoles fixedly secured to an arm extending outwardfrom the sides of said housing, a plurality of rotatable elementssecured to the under side of said housing and arranged for rotation onsaid upper platform, and means within said housing for rotating thehousing on said platform.

AUGUST LEIB.

WALTER KUHLEWIND.

an upper platform of insulating material, a shielded housing having a

